This invention relates to vehicle body constructions, and more particularly to a vehicle body construction having a back door-receiving opening and a drip trough adjacent the opening. Further this invention relates to a method of obtaining a vehicle body construction of the type adapted for having a back door assembly on the basis of a vehicle body construction of the type adapted for having a fixed rear window.
In order to meet the various demands of the automotive market, it is usual for automobile manufacturers to produce a series of automobile models based on a single basic chassis. For example, manufacturers usually offer a sedan, a hatchback, a coupe, a station wagon, etc. For the convenience of production of these models, it is essential to make use of the same parts and manufacturing processes as much as possible.
FIGS. 3 to 6 show two types of prior art vehicle body constructions--the type having a fixed rear window and the type having a back door--in which some of the parts employed therein are identical to each other.
That is, FIGS. 3 and 5 are sectional views showing a rear part of a vehicle body construction of the type having a fixed rear window, and FIGS. 4 and 6 are sectional views showing a rear part of a vehicle body construction of the type having a back door assembly.
As seen from the drawings, the vehicle body constructions are adapted to make use of the same roof panels 1 and rear fender outer panels 2. That is, each of the roof panels 1 has an outer exterior portion 1a defining the outer body of the vehicle and a bottom wall portion 1b spaced inwardly from the outer exterior portion 1a by an amount which is equal to that in the case of the other roof panel. Similarly, each of rear fender outer panels 2 has an outer exterior portion 2a defining the outer body of the vehicle and a bottom wall portion 2b spaced inwardly from the outer exterior portion 2a by an amount which is equal to that of the other rear fender outer panel. In the drawings, designated by the reference character G is a rear window glass panel, by S a sealant-adhesive, by 4 a weather strip, by 5 a back door assembly and by 6 a glass panel of the back door assembly 5. The vehicle body construction of the type having a back door assembly 5 shown in FIGS. 4 and 6 is provided with a drip channel or trough 3 for assuring the water-tightness of the vehicle body. The drip trough 3 is required for its intended purpose, to have a sufficiently large cross sectional area. However, the drip through 3 cannot be deepened since its depth is determined by the distance between the outer exterior portion 1a and the bottom wall portion 1b of the roof panel 1 which is also used in the vehicle body construction of the type having the fixed rear window shown in FIGS. 3 and 5. The drip trough is thus widened so as to have a sufficiently large cross sectional area, resulting in its having a width which is larger than its depth as shown. Because of the drip trough 3 thus shaped, the back door assembly 5 has a frame 5a which requires a thin, flat portion 5b for engagement with the weather strip 4 and an enlarged cross sectional portion 5c next to the thin, flat portion 5b to provide a sufficient rigidity of the frame 5a. The vehicle body construction of the type having a back door assembly as described above, encounters a drawback in that the widths 1.sub.1 and 1.sub.2 of the frame 5a are inclined to be considerably large thus resulting in a narrow vision area from the glass panel 6 and therefore a poor visibility of the vehicle as well as an unattractive appearance.